Honestly, i bike alot and also play 360 alot, so lets compare them
Bike- Outdoors, can go with friends, travel new places, cheaper than traveling in a car, good exercise, one time cost.
360- Fun to play, many games to buy, games are about 65$ each, if you get xbox live its about 50$ a year, so xbox will keep costing you in the long run. But if your willing to pay, then its up to you.